The key to preventive maintenance of CNC machine tools is to strengthen daily regular maintenance.The maintenance includes daily, weekly, monthly, quarterly,and semi-annual checks.The preventive maintenance of CNC machining machine tools is as follows:
1. Daily inspection of CNC machine tools
Its main projects include hydraulic system, spindle lubrication system, rail lubrication system, cooling system and air pressure system. Daily checks are based on normal conditions for each system. For example, when testing the process of the spindle lubrication system, the power lamp should be on and the hydraulic pump should be running normally. If the power light does not come on, the spindle should remain in a stopped state and contact the mechanical engineer. Make repairs.
2. Weekly inspection of NC machine tools
Its main items include machine tool parts and spindle lubrication system, weekly check should be correct, in particular machine tool parts should be removed iron filings and external debris.
3. Monthly inspection of NC machine tools
Mainly check the power supply and air dryer. Under normal conditions, the rated power supply voltage is 180-220 VOLTS and the frequency is 50 Hz. If there is any abnormality, it should be measured and adjusted. Air dryers should be removed once a month, cleaned and assembled.
4. Quarterly inspection of CNC machine tools
The quarterly inspection is mainly carried out from three aspects: machine bed, hydraulic system and spindle lubrication system. For example, when checking the bed, it depends on whether the accuracy and level of the lathe meet the requirements of the manual. If there is any problem, contact the mechanical engineer immediately. If there is a problem with the inspection of the hydraulic system and the spindle lubrication system, replace 60L and 20L new oil respectively and clean them.
5. Semi-annual inspection of CNC machine tools
After half a year, the hydraulic system, spindle lubrication system and X axis of the machine should be inspected. If there are any problems, it should be replaced with a new oil and then cleaned. After being fully familiar with and mastering the knowledge of preventive maintenance, we must also have a deeper understanding and necessary mastery of the cause and treatment of abnormal phenomena in oil pressure system. For example, when the oil pump does not spray oil, the pressure is abnormal and there is noise, we should know what the main reason is and what the corresponding solution is.
The causes and treatment of abnormal phenomena of oil pressure system should be understood from three aspects:
(1) The main reasons why the oil pump does not inject oil may include low fuel tank level, oil pump reverse, low speed, high oil viscosity, low oil temperature, filter blockage, suction pipe volume is too large, oil inlet suction, shaft and rotor damage, etc. There are corresponding solutions for the main causes, such as refueling, confirmation marks, replacement when the pump is reversed, etc.
(2) Abnormal pressure means that pressure is too high or too low. There are many main reasons, such as improper pressure setting, bad coil action of pressure regulating valve, abnormal pressure gauge, leakage of oil pressure system and so on. Solutions include disassembling and cleaning according to specified pressure Settings, replacing normal gauges, and checking each system in turn.
(3) Noise is mainly generated by oil pump and valve. When the valve has noise, the reason is that the flow exceeds the rated standard, the flow should be adjusted appropriately. When the oil pump has noise, there are many reasons and corresponding solutions, such as high viscosity and low oil temperature, the solution is to improve the oil temperature; When there are bubbles in the oil, air should be released from the system.